First of all, you need to work with dried twigs. You
can dry them carefully in an oven - at about 200 - 230 degrees. Or
just let them dry somewhere warm naturally.

You can strengthen your twigs with a product by Minwax
called wood hardener - available in most hardware stores. It is great
stuff for working with fragile natural materials. You mix it 50/50
with acetone.

For your glues, use tacky glue (thicker and less runny
than regular white glue) and Zap-A-Gap glue. It is a super glue, but
you can also use it to fill any gaps between the joint of two irregular
surfaces.

Get the spray accelerant that the Zap-A-Gap company
makes too. This, when squirted on the wet glue joint, will *instantly*
bond the glue. It is amazing and really helps. You can't easily clamp
of tape twig things while waiting for the glue to dry....

You can get this glue and accelerant from any good miniature
store. Earth and Tree
ships anywhere and they give great service.

If you have bad or messy glue joins to hide, you can
paint the glue with a mossy green-brown colored paint, or glue bits
of moss or tiny dried flowers over it: use your imagination!

To make to scale sizes, I recommend you measure real
furniture and then
divide your figures by 12 for the 1/12 size. You can also use an inexpensive
dollhouse doll and see if the doll fits.... or have regular dollhouse
furniture in front of you and hold up your twigs to each section as
you build.